Remote management of wireless devices is an essential aspect of offering enhanced services, such as multimedia services, in a wireless network. In order to remotely send management commands over the air to a wireless device, a device management server needs to know the identity of the device, whether the device is present on the network, and if so, where on the network the device can be found.
The basic network architecture of mobile wireless systems has evolved, resulting in several generations of wireless networks, including the current cellular systems exemplified by 2G and 3G networks. In 2G and 3G systems, the elements of the core network have a signaling interface that is based on IS-41 (using SS7 transport) and not on Internet Protocol (IP). However, this is beginning to change as some of the current and future deployments are beginning to support Internet Protocols in the core network (IMS-IP multimedia subsystems and 4G networks).
The core networks of the next generation of wireless communication systems will support IP, with the network elements supporting interfaces and functions found in the Internet. In such a system, wireless devices connect to the core network via wireless access points. To communicate on such a network, wireless communication devices will need to have IP addresses, and external hosts, such as device management servers, will need to know the IP addresses of the wireless devices in order to communicate with them. Furthermore, for devices with multiple interfaces, it will also be necessary to know the IP address for each interface along with the identity of the device.
In existing wireless networks, the presence of a device in the wireless network is detected by detecting wireless activity. Wireless activity indicates the presence of a device in the network but does not provide any information about the identity or a change in identity of the device. For example, the IP address of a device can expire or can be reassigned. In such a case, detection of activity in the wireless network alone is not sufficient for the device management server, which needs to know the current routable identity of the device such as the IP address of the device.
Furthermore, because the routable identity of the device such as the IP address or the network address may change, detecting the presence of a wireless device at the time of registration by a wireless network element such as a base station, or a home location register (HLR), is also not sufficient. Hence, in networks that support IP in the core, such as IP multimedia subsystems (IMS), WiMAX, or 4G wireless networks, the conventional approaches of IP detection are not viable.
Presently, a device management server sends notifications to wireless devices using SMS messages. SMS messages are sent using a fixed identity of the device, such as the phone number assigned to the device or MSISDN.
Newer, converged wireless devices, however, support interfaces for a conventional wireless network, a local area wireless network, and/or an IP wireless network. Such devices have a different set of identities that are visible at the core network or can be retrieved from the device. Examples of such identities include ESN, MEID, Stock Keeping Unit (SKU), BIOS string, MAC address, and IP address. These identities are typically sought by external systems such as device management servers. Some of these identities, however, including network addresses such as IP addresses, are not permanent and may change as well.
With converged devices supporting both a cellular interface and an internet interface, there is a need to send server-initiated notifications over the internet interface using the IP address of the device. The mapping of the phone number or MSISDN to a device IMEI is known to the management server and changes infrequently. When the association of the phone number or MSISDN to a given device changes, however, the decision to change the phone number for a given device is not typically made by network elements but by administrative entities, or at the request of the customer; i.e., external to the network. In systems such as GSM, a phone number is associated with a SIM card and any change in the association of a SIM card and a device results in a change in the mapping between MSISDN and the device.
There are mechanisms to communicate such changes to external systems. Typically, the HLR serves as the informing entity as the subscriber database is maintained by the HLR.
Unlike a phone number or MSISDN in a conventional wireless network, the IP address associated with a wireless device, in networks that support IP addressing of wireless devices, is more dynamic and can change, for example, due to mobility or expiry of the lease time for a give network address. The mapping of network addresses and device identities is typically determined by core network elements, such as a Dynamic Host Configuration Protocol (DHCP) server, for example. Alternatively, the network address of a device may be determined locally, such as in the case of a link-local address. A link-local address is an IP address constructed locally by a mobile device based on the hardware MAC address. This address can be used for IP communication within a local network without having to contact a server for address assignment. The network address assigned to a mobile device can change when the mobile device moves or is reassigned.
A need therefore exists for a mechanism by which the network address of a mobile device can be made available reliably and timely to any network elements or external elements that need to know the network address of the mobile device.